```
O
/ \
/ \
Sn = O
\ /
\ /
O
```
In the Lewis structure of SnO2, the tin (Sn) atom is in the center, surrounded by two oxygen (O) atoms. The tin atom has four valence electrons, while each of the oxygen atoms has six valence electrons. To achieve a stable electron configuration, the tin atom shares its four valence electrons with the two oxygen atoms, forming two Sn-O covalent bonds. Each oxygen atom shares two of its valence electrons with the tin atom, forming two O-Sn covalent bonds. This results in a total of four covalent bonds in the SnO2 molecule, with each atom having a complete octet of electrons.
The Lewis structure also shows the lone pairs of electrons on the oxygen atoms. Each oxygen atom has two unshared pairs of electrons, which are indicated by dots. The lone pairs of electrons are important for understanding the molecular geometry and properties of SnO2.
